Donald Farr has been a Mustang owner since 1970 and involved in the Mustang hobby as a journalist and editor since 1977. His first assignments were for the Shelby American Automobile Club and for a new magazine titled Mustang Monthly. In 1980, Farr joined Mustang Monthly to become the magazine’s first full-time editor. During his 18-year stint at Dobbs Publications, Farr authored Mustang Boss 302: Ford’s Trans-Am Ponycar and co-wrote How to Restore Your Mustang and the Mustang Recognition Guide with Mustang Monthly founder Larry Dobbs. Farr later edited Musclecar Review and Super Ford magazines before moving into a full-time Editorial Director position at Dobbs. When Dobbs was purchased by Petersen Publishing in 1998, Farr became editor of Mustang & Fords magazine. For a brief time, Farr left the print world to work at Mustangweekly.com before returning to his roots at Mustang Monthly from 2003-2014.

Farr is currently employed by Pate Media Group as editor of Mustang Times, the official publication of the Mustang Club of America.

In 1987, Farr wrote an editorial about Ford’s plans to convert the Mustang to front-wheel drive and asked readers to write Ford in protest. Over 30,000 letters flooded Ford World Headquarters, convincing Ford to change its plans for the Mustang. The front-wheel drive platform became the Probe, while plans were started to continue the rear-wheel-drive Mustang as the new 1994 model.

In 2010, Ford Motor Company commissioned Farr to revise his original Boss 302 book with new chapters about the 2012 Boss 302. The updated book, Mustang Boss 302: From Racing Legend to Modern Muscle Car, was published by Motorbooks in July 2011 and has been updated in a second printing to incorporate the 2013 Boss 302.

Farr’s Mustang: Fifty Years, Ford’s official Mustang 50th anniversary publication, was published by Motorbooks in October 2013. Art of the Mustang, with "light-painting" photography by Tom Loeser, was published in October 2015.

In January 2017, Motorbooks published Farr's Ford Mustang: America's Original Pony Car as a revised version of Mustang Fifty Years with an added chapter chronicling the development of the 2015 S550 Mustang, complete with details about the 2015-17 models, including the 50th Anniversary Special Edition and Shelby GT350/GT350R.

Farr received a Lifetime Appreciation Award from Ford’s Team Mustang in 2011 and the Lee Iacocca Award in 2012. He was inducted into the Mustang Club of America’s Mustang Hall of Fame in 2012.

Farr currently owns the 1966 Mustang GT hardtop that his grandfather purchased new in 1966.